#include <bits/stdc++.h>
#define int long long
#define ll long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define F first
#define S second
using namespace std;
int N, M, Q, t, child[100005], pre[100005][20], S[100005], T[100005], L[100005];
ll X[100005], Y[100005];
pii io[100005], range[100005];
vector<pii> E[100005];
pll check[100005];
struct BIT
{
ll bit[100005];
void init()
{
for (int i = 0; i <= N; i++)
bit[i] = 0;
}
void modify(int pos, ll val)
{
assert(pos != 0);
for (; pos <= N; pos += (pos & -pos))
bit[pos] += val;
}
ll query(int pos)
{
ll ans = 0;
for (; pos > 0; pos -= (pos & -pos))
ans += bit[pos];
return ans;
}
} bit;
bool ischild(int r, int c)
{
if (io[r].F <= io[c].F && io[c].S <= io[r].S)
return 1;
return 0;
}
int lca(int u, int v)
{
int l = u;
for (int p = 19; p >= 0; p--)
if (pre[l][p] && !ischild(pre[l][p], v))
l = pre[l][p];
if (!ischild(l, v))
l = pre[l][0];
return l;
}
void dfs(int u)
{
io[u].F = ++t;
for (auto [v, i] : E[u])
if (v != pre[u][0])
{
child[i] = v;
pre[v][0] = u;
for (int p = 1; p < 20; p++)
pre[v][p] = pre[pre[v][p - 1]][p - 1];
dfs(v);
}
io[u].S = t;
}
signed main()
{
cin >> N >> M >> Q;
for (int i = 1; i < N; i++)
{
int u, v;
cin >> u >> v;
E[u].emplace_back(pii(v, i));
E[v].emplace_back(pii(u, i));
}
for (int i = 1; i <= M; i++)
cin >> check[i].S >> check[i].F;
sort(check + 1, check + 1 + M);
dfs(1);
//cerr << "dfs\n";
vector<pii> query, nxt;
for (int i = 1; i <= Q; i++)
{
cin >> S[i] >> T[i] >> X[i] >> Y[i];
L[i] = lca(S[i], T[i]);
range[i] = pii(0, M);
query.emplace_back(pii(i, (range[i].F + range[i].S + 1) / 2));
}
//cerr << "lca\n";
int iter = 20;
while (iter--)
{
int qdx = 0;
bit.init();
for (int i = 0; i <= M; i++)
{
vector<pii> suc, fail;
if (i)
{
bit.modify(io[child[check[i].S]].F, check[i].F);
bit.modify(io[child[check[i].S]].S + 1, -check[i].F);
}
while (qdx < query.size() && query[qdx].S == i)
{
int j = query[qdx].F;
if (bit.query(io[S[j]].F) + bit.query(io[T[j]].F) - 2 * bit.query(io[L[j]].F) <= Y[j])
{
range[j].F = query[qdx].S;
suc.emplace_back(pii(j, (range[j].F + range[j].S + 1) / 2));
}
else
{
range[j].S = query[qdx].S - 1;
fail.emplace_back(pii(j, (range[j].F + range[j].S + 1) / 2));
}
//cerr << j << ' ' << range[j].F << ' ' << range[j].S << ' ' << bit.query(io[S[j]].F) + bit.query(io[T[j]].F) - 2 * bit.query(io[L[j]].F) << '\n';
qdx++;
}
for (auto p : fail)
nxt.emplace_back(p);
for (auto p : suc)
nxt.emplace_back(p);
}
query.clear();
query.swap(nxt);
//cerr << "bs iter " << iter << '\n';
}
bit.init();
int qdx = 0;
for (int i = 1; i <= M; i++)
{
bit.modify(io[child[check[i].S]].F, -1);
bit.modify(io[child[check[i].S]].S + 1, 1);
}
for (int i = 0; i <= M; i++)
{
vector<pii> suc, fail;
if (i)
{
bit.modify(io[child[check[i].S]].F, 1);
bit.modify(io[child[check[i].S]].S + 1, -1);
}
while (qdx < query.size() && query[qdx].S == i)
{
int j = query[qdx].F;
X[j] += bit.query(io[S[j]].F) + bit.query(io[T[j]].F) - 2 * bit.query(io[L[j]].F);
qdx++;
}
}
//cerr << "calc ans\n";
for (int i = 1; i <= Q; i++)
{
//cout << range[i].F << ' ';
cout << max(-1LL, X[i]) << '\n';
}
}
